Pronounced (at-um-esque)proper noun: It means "Strength of Chaos". Atemesque is the name of the mythical "Black Phoenix", which in mythology is said to be the only thing that could kill a phoenix indefinitly. It is also said that the spirit of Atemesque could possess those in dire situations and give them otherworldly strength.

Dave: Did you hear about the guy who saved that girl inthe earthquake?
Trey: Yeah he held up a falling wall so she could crall out of the rubble right?
Davey: Maybe he was possessed by the Atemesque!
Trey: Your so superstitious, that's just a myth!